Process for breaking petroleum emulsions



Patented July 22, 1941 PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, University City, and Bernhard Keiser, Webster Groves, Mo., assignors to Petrolite Corporation, Ltd., Wilmington, Del., a corporation of Delaware No Drawing.

Application June 27, 1940,

Serial No. 342,730

9 Claims. (01.252-341) This invention relates primarily to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose 'of separating the oil from the water.

One'object of our invention is to provide a novel process 'for resolving petroleum emulsions of the water-in-oil type, that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprises fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil whichconstitutes the continuous phase of the emulsion.

Another object of our invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude tics and are derived from somewhat difierent sources and are different in structure, but can be included in the broad generic term previously indicated.

Among sources of such acids may be mentioned straight chain and branched chain, saturated petroleum and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned is of significant value in removing impurities, particularly inorganic salts, from pipeline oil.

The demulsifier or demulsifying agent employed in our process consists of a compound or mixture of compounds that comprises the esterification product of a high molecular weight carboxy acid or its equivalent and a hydroxylated tertiary methylene diamine of the kind hereinafter described. Said compound or mixture of compounds is characterized by the presence of an acyl radical'derived from a suitable high molecular weight carboxy acid of thekind which will be described in detail subsequently.

In order that our invention may be clearly understood, we will hereinafter give several examples of chemical compounds suitable for use in practising our process; and we will explain how said compounds can be produced or obtained.

The expression.higher molecular weight carboxy acids is an expression frequently employed to refer to certain organic acids, particularly monocarboxy acids, having more than six carbon atoms, and generally less than 40 carbon atoms. The commonest examples include the detergentforming acids, i. e., those acids which combine with alkalies' to produce soap or soap-like bodies. The detergent-forming acids, in turn, include naturally-occurring fatty acids, resin acids, such as abietic acid, naturally-occurring petroleum acids, such as naphthenic acids, and carboxy acids produced by the oxidation of petroleum. As will be subsequently indicated, there are other acids which have somewhat similar characterisand unsaturated, carboxylic, aliphatic, alicyclic, fatty, aromatic, hydroaromatic, and aralkyl acids, including caprylic acid, butyric acid, heptylic acid, caproic acid, capric acid, pimelic acid, sebacic acid, erucic acid, saturated'and unsaturated higher molecular weight aliphatic acids, such as the higher fatty acids containing at least eight carbon atoms, and including, in addition to those mentioned, melissic acid, stearic acid, ol-eic acid, ricinoleic acid, diricinoleic acid, triricinoleic acid, polyricinoleic acid, ricinostearolic acid, ricinoleyl lactic acid, acetylricinoleic acid, chloracetyl-ricinoleic acid, linoleic acid, linolenic acid, lauric acid, myristic acid, undecylenic acid, palmitic acid, mixtures of any two or more of the above mentioned acids or other acids, mixed higher fatty acids derived from animal or vegetable sources, for example, lard, cocoanut oil, rapeseed oil, sesame oil, palm kernel oil, palm oil, olive oil, corn oil, cottonseed oil, sardine oil, tallow, soyabean oil, peanut oil, castor oil, seal oils, whale oil, shark oil, and other fish oils, teaseed oil, partially or completely hydrogenated animal and vegetable oils, such as those mentioned; hydroxy and alpha hydroxy higher carboxylic, aliphatic and fatty acids, such as dihydroxystearic acid, dihydroxy palmitic acid, hihydroxybehenic acid, alphahydroxy capric acid, alphahydroxystearic acid, alphahydroxy palmitic acid, alphahydroxy lauric acid, alphahydroxy myristic acid, alphahydroxy cocoanut oil mixed fatty acids, alphahydroxy margaric acid, alphahydroxy arachidic acid, and the like; fatty and similar acids derived from various waxes, such as beeswax, spermaceti, montan wax, Japan wax, coccerin, and carnauba wax. Such acids include carnaubic acid, cerotic acid, lacceric acid, montanic acid, psyllastearic acid, etc. As suggested, one may also employ higher molecular weight carboxylic acids derived, by oxidation and other methods, from parafl'in wax, petroleum and similar hydrocarbons; resinic and hydroaromatic acids, such as hexahydrobenzoic acid, hydrogen- Other suitable acids include phenylstearic acid, benzoylnonylic acid, campholic acid, fencholic acid, cetyloxybutyric acid, cetyloxyacetic acid, chlorstearic acid, etc.

It is also well known that diamines, and particularly those having pronounced basic properties, may be derived by various means, provided that the resultant diamine is characterized by the fact that the two amino nitrogen atoms are not attached to the same carbon atom. Such diamines, generally referred to as alkylene diamines, are well known and may be characterized by ethylene diamine. Derivatives of the diamines herein contemplated are characterized by being a methylene diamine derivative, i. e., a derivative of the hypothetical methylene diamine:

Methylene diamine is almost unknown for practical purposes, since it is very unstable in theform of a free base, but does exist in the form of alkylated or acylated derivatives. In view of this fact, it becomes obvious that the new chemical compound or composition of matter previously referred to must necessarily be obtained indi-.

rectly, insofar that the parent diamine is almost non-existent.

It is well known that a large number of secondary amines are available which may be designated by the formula type:

in which B represents an alkyl, aralkyl, alicyclic, aryl, alkylol, aralkylol, hydroxy alicyclic, heterocyclic, or other equivalent radical; and B" an alkylol, aralkylol, hydroxy alicyclic, or similar radical. Similarly, the formula The amine so produced may be indicated by the following formula:

'r /NB" in which, as has been previously pointed out, T may represent a hydrogen atom derived from formaldehyde, or may represent a radical derived from acetaldehyde, propionaldehyde, butyraldehyde, heptaldehyde, lauric aldehyde, palmitic aldehyde, or stearic aldehyde, etc. Naturally, B" may occur more than once, and Bf less than three times. Similarly, instead of aliphatic aldehydes, one may employ heterocyclic aldehydes, such as furfuraldehyde, or aromatic aldehydes, such as benzaldehyde. One may also employ alicyclic aldehydes, such as hexahydrobenzaldehyde. Unsaturated aldehydes, such as acrolein, crotonaldehyde, or tiglic aldehyde, may be employed. As previously indicated, B may represent radicals, such as methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, decyl, hexadecyl, octadecyl, or similar radicals. Similarly, B may represent an alkyl radical, such as a benzyl radical, ethyl benzyl radical, dimethyl benzyl radical, an alicyclic radical, such as the cyclohexyl, methyl cyclohexyl, etc.; likewise, B, as well as B", may represent the radicals hydroxy ethyl, hydroxy propyl, hydroxy butyl, and other similar radicals, including 'a C6H4C2H4OH radical, or, a CsHmOH radical. Other radicals include the furfural radical, or hydroxy derivatives thereof. Piperidine may be considered as a special adaptation, in which one radical replaces two amino hydrogen atoms. As previously indicated, B may be selected from any of the type of radicals above mentioned; whereas, B" is limited to those radicals in which there is an alcoholic hydroxy group present, such as an alkylol radical, etc.

It is to be noted that the methylene diamine, expressed by the above formula, is a tertiary diamine in the sense that neither amino nitrogen atom has attached thereto a replaceable hydrogen atom. For convenience, the above formula may be rewritten as follows, so as to indicate that there is present an alcoholic hydroxyl radical:

'r\ /N-B OH U N B B a in which B"OH is obviously the monovalent hydro y hydrocarbon radical, such as an alkylol radical or the like. It is well known that amines, particularly non-aryl, such as triethanolamine or the like, can be acylated by reaction withv fatty acids, or a suitable functionalderivative thereof, such as the acyl chloride, or the anhydride, or even the ester. If the tertiary hydroxy methylene diamine of the kind just described is reacted with a detergent-forming monobasic carboxy acid, the reaction may be indicated in the following manner:

with the formation of an intermediate ester, WhlCh may be indicated in the following manner:

B! 'r NB.OOC.R

'r NB An examination of the previous formulas reveals that the hydroxylated tertiary acylated methylene diamine must contain at least one hydroxyl, and might contain as many as nine hydroxyls available for esterification; and as a matterof-fact, might contain an even greater number if, instead of using the secondary amine, such as diethanolamine, dipropanolamine, dibutanolamine, etc., one employed ethanolglycerylamine, propyl glycerylamine, or diglycerylamine. Amines derived from diglycerol instead of glycerol would furnish radicals containing three hydroxyls, even after attachment to the amino nitrogen atom. If, in all instances, B and B"' are derived from diglycerylamine, there would be present at least sixteen hydroxyls, and there might be present at least one more if aldol or a higher homologue were employed as a reactant in formation of the intermediate ester.

In addition to aldol, other similar hydroxy aldehydes or aldehyde-alcohols may be employed. As tosuch aldehydes other than aldol, reference is made to Richters Organic Chemistry, (Allott) volume 1, third English edition, 1934, pages 389- 391.

In view of what has been said previously, it does not appear necessary to enumerate various suitable amines which may be employed for reaction with a selected aldehyde, but it may be well to indicate that among those which may be employed are the following: diethanolamine, di-

propanolamine, dibutanolamine, dioctanolamine,

dipentanolamine, glyceryl hexanolamine, methyl glycerylamine, ethyl glycerylamine, propyl glycerylamine, cyclohexyl glycerylamine, benzyl glycerylamine; dibenzylamine, ethyl benzylamine, methyl benzylamine, propyl benzylamine, phenylmonoethanolamine, naphthylmonoethanolamine, cyclohexyl ethylamine, 'cyclohexyl propylamine, cyclohexyl hexylamine, diethylamine, dipropylamine, diamylamine, dihexylamine, dioctylamine, diglycerylamine, etc. In all the previous examples each radical indicates a substitute for an amino hydrogen atom. Similarly, amines can be obtained from polyglycerols or polyglycols, as, for instance, the secondary amines, indicated by the following formulas:

C2H4OC2H4OH C2H40 C2H4OH C2H4OC2H4OH C2H4OH C2H4OC2H4OH HN\ C2115 Such amines may serve as functional equivalents of the previously described amines, which happen to be free from an ether linkage. Likewise, one may have amines in which there is more than one ether linkage, i. e., in which the hydrocarbon radical which replaces an amino hydrogen atom has been interrupted more than once by an oxygen atom.

In examining the previous formulas, it becomes evident that if two different amines are employed, one of which does not contain a hydroxylated hydrocarbon radical, then the reaction is not limited to two dissimilar amines, but may take place in part in such a manner as to involve two similar amines, i. e., the aldehyde may react with two molecules of the hydroxylated amine; it may react with one mole of the hydroxylated amine and one mole of the non-hydroxylated amine; or it may be united with two moles of the nonhydroxylated amine. In such event, as last mentioned, the resultant compound is without value, unless a hydroxy aldehyde, such as aldol, has been employed. In such event an attempt to esterify with a detergent-monocarboxy acid, or the like, results in the formation of an entirely different type of material, i. e., an acid radical being introduced into the aldehyde radical or residue as differentiated from the amine radical residue. For practical purposes, then, it is most expedient to manufacture or produce a methylene diamine from a single kind of secondary amine; and in such event, obviously it must be a hydroxylated amine, such as diethanolamine, except if one uses aldol or the like. In subsequent examples, dieth'anolamine is employed as the secondary amine for reaction with the aldehyde; but in view of what has been said previously, various other secondary amines or mixtures thereof might be employed.

Attention is again directed to the fact that wherever a hydroxyl radical exists, and provided it is not necessary for subsequent reaction, then such hydroxyl radical could be reacted with an acid, such as acetic acid, butyric acid, heptoic acid, etc.; and this statement applies to the hydroxyl radical of an alcohol aldehyde, such as aldol. Furthermore, an alkylol radical might be so combined as has been previously pointed out, or the alcohol radical or its equivalent might be combined with a monohydric alcohol. In essence, such combination simply results in the hydrocarbon chain interrupted at least once by an oxygen atom, as differentiated from an uninterrupted hydrocarbon chain. In the hereto appended claims reference to an alkyl, alkylol, or similar radical is intended specifically to include such examples where there is interruption of the chain or ring by an oxygen atom.

Having obtained the hydroxylated tertiary methylene diamine of the kind described in an anhydrous state or approximately anhydrous state, the next step is to obtain acylation by means of a high molal carboxy acid and more particularly, a detergent-forming acid. Such procedure is comparable to the type of reaction in which other well-known hydroxylated amines are esterified, i. e. made or caused to act like an alcohol. For instance, it is comparable to the reaction by which a fatty acid radical, such as the ricinoleic acid radical is introduced into a hydroxylated tertiary amine. The same procedure is employed, for example, in introducing a high molal carboxy acid radical into a compound such as tetra hydroxyethyl ethylene diamine or triethanol amine. See U. S. Patents 2,167,347 and 2,- 167,348, to De Groote, Keiser, and Blair, issued July 25, 1939.

Briefly stated, the method of producing such reactions is as follows: The acid, particularly a fatty acid or its functional equivalent, is reacted with a tertiary hydroxylated amine under such conditions so as to remove any water which may be formed. The temperature, generally speaking, is above the boiling point of water, i. e., above C. and below the decomposition point of the amine. Since hydroxylated amines are generally high boiling, the reaction can be conducted at a considerably higher temperature, -180 or even higher, provided that one does not employ a temperature which results in the pyrolysis or decomposition of the amine. Instead of the acid itself, obvious functional equivalents, such as the anhydride, the acyl chloride, an ester, or an amide may be employed. The entire object is to use a compound which has a labile acyl group, or to state the matter another way, is in essence an acylating or oxy-acylating agent insofar that the oxy-acyl or more correctly the acyloxy group, is introduced. One can, of course, view the alcohol radical as losing either a hydrogen atom or hydroxyl radical. Needless to say, when compounds such as the acyl chloride, ester or amide are employed, some compound other than water is split off, for instance, an alcohol or ammonia or hydrochloric acid. There are certain objections to the use of acyl chloride in that one obtains the salt of the compound, i. e., the acid chloride, which may not be as desirable as the unneutralized base. The mass may be heated during the reaction period, and the reaction period may vary from 2-8 hours. If desired, an inert gas such as nitrogen may be passed through the mixture while being reacted.

Our preferred reagent is obtained in the following manner:

We react a readily available aldehyde, such as acetaldehyde' or heptaldehyde, in the molecular proportions of one mole of aldehyde with two moles of diethanolamine. Such reaction is conducted in the manner previously noted; and after completion of reaction, anywater still present which has not been removed previously in the course of reaction is removed by distillation, preferably under vacuum.

Such hydroxylated diamine is then treated in the proportion of three moles of diamine to two moles of castor oil, which consists essentially of triricinolein. Any suitable quantity of material may be employed, for instance, 500 lbs. of the selected anhydrous diamine and the appropriate amount of castor oil. The two products are mixed together and heated at a reasonable temperature above the boiling point of water and below the point of decomposition, for instance, at some temperature between 135-195 C. for a suitable period of time, i. e., 1 to 5 hours. Constant stirring may be employed if desired. Also one may pass dried nitrogen gas through the reaction mass. The product so obtained is the acylated diamine mixed with some free glycerol and certain other accompanying cogeneric products.

It is to be noted that the compounds described are basic in character due to the presence of an unacylated basic amino nitrogen atom, or due to the presence of an esterified group of the kind described. In such instances the compound may be employed as such, or may be employed in basic form, (i. e., after combination with water) or may be employed in salt form by reaction with an acid such as acetic acid, lactic acid, hydrochloric acid, or any other suitable acid.

It is to be noted that the procedure previously described can be employed to introduce one or more acyl radicals into a hydroxylated tertiary methylene diamine of the kind described. The introduction of more than one acyl radical, of course, obtained from a high molecular weight carboxy acid or the like is predicated on the presence of more than one alcoholic hydroxyl radical. Obviously the product obtained in the manner described in preparation of the preferred reagent would yield a product containing four hydroxyl radicals. It is our preference to introduce at least one acyl radical and preferably not more than two. The most desirable reagents are those which are obtained by the introduction of a single acyl radical derived from a high molecular weight carboxy acid and more particularly, from the detergent-type acid. The fatty acids yield the most desirable compounds, and recinoleic acid represents the most desirable type of fatty acid. It has been previously pointed out that the amino nitrogen atoms present are in basic form and that either one or both nitrogen atoms may be combined with water or a suitable acid; or the comppunds can be employed in uncombined form, i. e., in the form of a free base.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water-petroleum hydrocarbons, such as gasoline, kerosene, stove oil, a coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials employed as the demulsifying agent of our process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone, or in admixture with other suitable well known classes of demulsifying agents. I

It is well known that conventional demulsifying agents may be used in a. water-soluble form,

or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively limited oil solubility. However, since such reagents are sometimes used in a ratio of 1 to 10,000 or 1 to 20,000 or even 1 to 30,000, such apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility Within the concentration employed. This same fact is true in regard to the material or materials employed as the'demulsifying agent of our process.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our process is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described Will find comparatively limited application, so far as the majority of oil field emulsions are concerned; but we have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

In practicing our process, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various ways, or by any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used either alone, or in combination with other demulsifying procedure, such as the electrical dehydration process.

The demulsifier herein contemplated may be employed in connection with what is commonly known as down-the-hole procedure, i. e., bringing the demulsifier in contact with thefluids of the well at the bottom of the Well or at-some point prior to the emergence of said well fluids. This particular type of application is decidedly feasible when the demulsifier is used in connection with acidification of calcareous oil bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a hydroxylated tertiary methylene diamine; said acyl radical being derived from a high molecular weight carboxy acid.

2. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a deinulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a hydroxylated tertiary methylene cliamine; said acyl radical being derived from a detergent-forming acid.

3. A process for breaking petroleum emulsions of'the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a hydroxylated tertiary methylene diamine; said acyl radical being derived from a higher fatty acid having more than 8 and not over 22 carbon atoms.

4. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a hydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid.

5. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substitucnt for a hydrogen atom of a polyhydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid.

6. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a poly? hydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid; said amine bein characterized by the presence of at least two and not more than four alkylol radicals.

'7. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a sulzstituent for a hydrogen atom of a polyhydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid; said amine being characterized by the presence of at least two and not more than four hydroxy ethyl radicals.

8. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing at least one acyl radical as a substituent for a hydrogen atom of a polyhydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid; said amine being characterized by the presence of four hydroxy ethyl radicals.

9. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier comprising an esterification product derived by introducing a single acyl radical as a substituent for a hydrogen atom of a polyhydroxylated tertiary methylene diamine; said acyl radical being derived from ricinoleic acid; said amine being characterized by the presence of four hydroxy ethyl radicals.

MELVIN DE GROOTE. BERNHARD KEISER. 

